The present invention relates to implements such as knives and tools having folding blades or tool bits, and particularly to a frame member having a flange including an integral leaf spring.
Most folding knives or tools have a spring of some fashion which interacts with a folding blade or bit to hold the blade or bit in folded or extended position relative to the handle. Such springs are typically biased to bear against the cam-shaped base of the folding blade or bit. The cam on the base is shaped such that increased force is required to move the blade or bit into or out of extended or folded position. The spring also applies a frictional force to the base as the blade or bit is being moved between folded and extended positions. For example, traditional folding pocket knives include an independent back spring, separate from and fastened to the frame or scales of the knife, that bears against the base of the blade. Folding multipurpose tools such as shown in U.S. Pat. Nos. 4,238,862, 5,697,114, 5,745,997 and 6,293,018 employ leaf springs, integral with a portion of the tool frame, to bear against the base of a blade or bit. These leaf springs are typically cut from a portion of a frame member and are located within a channel formed by one or more frame members. The folding multipurpose tool shown in U.S. Pat. No. 5,745,997 includes both an integral leaf spring and two independent beam springs arranged within a channel-shaped frame member. U.S. Pat. No. 6,014,787 discloses integral leaf springs located in the floor and sidewall of a channel-shaped frame member.